Session: 04-02: SMRs, Advanced Reactors and Fusion

Paper Number: 134526

134526 - Assessment of Emergency Planning Zone for Small Modular Pressurized Water Reactors Based on the Risk-Informed Methodology 

Abstract: 

More than 100 concepts and designs of Small Modular Reactors(SMRs) are under development worldwide. SMRs usually have the characteristics of integrated design, modular manufacturing and installation, high safety, and proximity to users, and have broad prospects for development and application. The principles and methods for the emergency planning zone sizing of large pressurized water reactors in China are mainly based on the national standard - Criteria for emergency planning and preparedness for nuclear power plants - Part 1: The dividing of emergency planning zone. Due to the lower power levels and passive safety features of SMRs, the radioactive releases, both in magnitude and frequency, would be significantly lower than that of large reactors. Too large EPZ size may decrease flexibility and limit the deployment of SMRs. How to reasonably determine the emergency planning zone of small reactors has become a focus in the nuclear industry. Based on the risk-informed methodology recommended by IAEA-TECDOC-1652, considering both the frequency of occurrence of the entire spectrum of accident scenarios and the dose consequence analysis for each scenario, this paper analyzes and calculates the emergency planning zone size of a small modular pressurized water reactor in China using the Level-2 PSA (Probabilistic Safety Analysis) source terms of severe accidents and the site actual meteorological data. Based on the best estimate, realistic models, the dose absorbed by a hypothetical individual located at different distances from the site is calculated. Choosing a limiting dose of 10mSv and a limiting frequency of 1.0E-08/ry, the preliminary recommended emergency planning zone size is about 500m. Even in the conservative meteorological conditions, the emergency planning zone size is about 1.6km, which shows a significant reduction than that of large reactors. The risk-informed methodology, which builds on the concept of risk, is an application of Level-3 PSA supporting in the definition and sizing of the emergency planning zone, and could better verify the safe design of SMRs in the determination of emergency planning zones, and the boundary of the emergency planning zone is more in line with the characteristics of SMRs by comprehensively considering both the impact of accident frequency and the dose consequences. In addition, when determining the actual boundary of the emergency planning zone of SMRs, it is also necessary to consider the site characteristics, public psychological factors, and actively carry out nuclear power knowledge popularization to further improve the public's acceptance and recognition of SMRs and promote their safe and reliable deployment worldwide.

Presenting Author: Mengxi Wang China Nuclear Power Engineering Co.,LTD

Presenting Author Biography: Mengxi WANG, received the B.S. degree in Nuclear Science and Engineering from Tsinghua University, Beijing, China, in 2012 and the M.S. degree in Nuclear Science and Technology from BINE, Beijing, China, in 2015. She is currently working as a senior engineer in China Nuclear Power Engineering Co.,LTD, and focusing on nuclear safety and emergency preparedness of NPPs.

Authors:

Mengxi Wang China Nuclear Power Engineering Co.,LTD
Nan Wu China Nuclear Power Engineering Co.,LTD
Qun Cao China Nuclear Power Engineering Co.,LTD
Jin Yan China Nuclear Power Engineering Co.,LTD.
Jiaxuan Gao China Nuclear Power Engineering Co.,LTD.
Jiemin Zhang China Nuclear Power Engineering Co.,LTD
Na Xue China Nuclear Power Engineering Co.,LTD